SynopsisSunscreens provide broad-spectrum UV skin protection and contain more often UV filter combinations. Their efficacy reducing skin photo carcinogenesis and photo ageing is widely documented. However, there are many concerns about UV filter safety. Organic UV filters were the first targeted by scientist concerns, as they were showed to trigger skin allergic reactions. Inorganic UV filters were then at the heart of scientist debate especially because of their nanometric size. Over the last years, many studies have been published tending to highlight that organic as well as inorganic UV filters could lead to variable side effects after sunscreen application. However, these studies are still very controversial due to different experimental conditions and models. This review reveals that complementary studies using standardized methods are mandatory before ascertaining that UV filters threaten human health. R esum eLes produits solaires destin es a prot eger la peau contre les irradiations UV contiennent le plus souvent des combinaisons de filtres UV. Ces filtres permettent de r eduire le vieillissement pr ematur e de la peau ainsi que la survenue de cancer cutan e. Cependant, la nocivit e des filtres UV est toujours un sujet de controverse. Ainsi, des r eactions allergiques li ees a l'utilisation de produits solaires contenant des filtres UV organiques ont et e rapport ees dans la litt erature. R ecemment, l'utilisation de filtres UV min eraux a l' echelle nanom etrique, dispers es dans les produits destin es a la protection solaire a fait l'objet de travaux scientifiques visant a etablir le niveau de p en etration cutan ee. Ces derni eres ann ees, de nombreuses etudes ont et e publi ees tendant a montrer que les filtres UV organiques et inorganiques peuvent entrainer divers effets ind esirables. Mais, ces diverses etudes restent tr es controvers ees notamment a cause des diff erences dans les conditions exp erimentales et les mod eles utilis es. Cette revue r ev ele que des etudes compl ementaires utilisant des m ethodes standardis ees sont n ecessaires pour confirmer ou infirmer que les filtres UV pr esentent un risque sanitaire.

The obtained results demonstrate the interest of these gelled nanoparticles and their aqueous dispersion for the preparation of new formulations for cosmetic and dermo-cosmetic applications.

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To the editorEx vivo and in vitro skin permeation tests are extensively used to evaluate transcutaneous penetration of drugs. However, surprisingly little attention is paid to the tissue morphology during such studies. We want to strike a cautionary note, important for the interpretation of experiments predicting transcutaneous drug absorption in vivo.Transcutaneous diffusion devices, called Franz cells, are most frequently used. Excised skin is positioned between the 'donor' and 'receiver' compartments of the device. The studied molecule applied to the 'donor' chamber must cross the skin barrier to be subsequently quantified in the 'receiver' fluid. Because of its availability in large quantities and its similarity to human skin, pig skin is frequently used for the tests (1). In accordance with the international recommendations, skin samples are stored at À20°C and thawed before experiments (S1). However, contradictory reports exist in the literature concerning the validity of the procedure (2,3). Most of the studies focus on the permeation results alone (S2, S3).Ensuring that the skin permeability barrier maintains its integrity prior to the tests is essential for the successful interpretation of permeation experiments and accurate prediction of the studied molecule's behaviour in vivo. We evaluated the impact of freezing on porcine skin morphology and permeability. A detailed approach is described in the Data S1. Fresh skin samples from pig ear (0.7 mm thick) were compared with one or four times frozen, and ether-/chloroform-delipidated skin from nine animals. Skin biopsies were taken for ultrastructural studies prior to the permeability tests with 1% aqueous caffeine solution, a molecule recognized as a reference permeation compound. Caffeine was quantified in the 'receiver' compartment of Franz cells, filled with PBS, with highperformance liquid chromatography at different time-points during the 24-h experiment. Two model parameters were calculated by fitting the data of measured caffeine amount per unit of skin surface (Q t ) versus time (t) to the following equation:where D is the diffusion constant thought the skin, K is the partition coefficient between skin and vehicle and L is the drug pathway length. The permeability parameters D/L² and KL allow the estimation of the steady-state skin permeability coefficient Kp of caffeine such as:

Skin and mucosal infections constitute recurrent pathologies resulting from either inappropriate antiseptic procedures or a lack of efficacy of antimicrobial products. In this field, nanomaterials offer interesting antimicrobial properties (eg, long-lasting activity; intracellular and tissular penetration) as compared to conventional products. The aim of this work was to produce, by a new solvent-free process, a stable and easily freeze-dryable chlorhexidine-loaded polymeric nanocapsule (CHX-NC) suspension, and then to assess the antimicrobial properties of nanomaterials. The relevance of the process and the physicochemical properties of the CHX-NCs were examined by the assessment of encapsulation efficiency, stability of the nanomaterial suspension after 1 month of storage, and by analysis of granulometry and surface electric charge of nanocapsules. In vitro antimicrobial activities of the CHX-NCs and chlorhexidine digluconate solution were compared by measuring the inhibition diameters of two bacterial strains ( Escherichia coli and Staphylococcus aureus ) and one fungal strain ( Candida albicans ) cultured onto appropriate media. Based on the findings of this study, we report a new solvent-free process for the production of nanomaterials exhibiting antimicrobial activity, suitable stability, and easily incorporable as a new ingredient in various pharmaceutical products.

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